Reed with curved taper



H. E. W. BO

REED WITH CURVED TAPER Filed oct. s. 1962 4l 'E6 E /xwflllum uw! i AllUnited States Patent O 3,154,997 REED WITH CURVED TAPER Harald E. W.Bode., North rEonawanda, NY., assigner to The Wurlitzer Company,Chicago, Ill., a corporation of Ohio Filed Oct. 3, 1962, Ser. No.228,103 V6 Claims. (Sl. 84-4ti8) reeds in an electronic piano. Twodiltculties have been encountered here; one in the stresses imposed onthe reeds, and another in the inherently different vibrationalcharacteristics of reeds as contrasted to strings.

An impulsively actuated reed is practically instantaneously driven to alarge excursion, and thereafter is allowed to vibrate in free, decadentfashion. The shock of the impulse actuation is quite substantial, andboth this shock and the initially rather great excursion of the reedtend to break the reed. As a result, the useful life of an impulsivelyactuated reed is quite Asubstantially less than that of the practicallyiniinite life of a wind driven reed which is not subjected to shockloading, nor to great excursions.

Accordingly, it is an object of this invention to provide an improvedreed for use in an electronic piano which will far outlast conventionalreeds.

Yet another object of this invention is to provide a reed for use in anelectronic piano, which reed has no well-defined breaking point.

As is well known, a vibrating string vibrates essentially with afundamental and a plurality of harmonics. A reed, on the other hand,vibrates essentially with a fundamental and with a series of inharmonicpartials. Thus, a reed piano inherently tends to sound somewhatdifferent from a string piano.

ln view of the foregoing, it is yet another object of this invention toprovide a vibratory reed for an electronic piano which will produce aremarkably piano-like tone.

Other and further objects and advantages of the present invention willbe apparent from the following description when taken in connection withthe accompanying drawings wherein:

FIG. l is a cross sectional view through a piano action constructed inaccordance with the principles of the present invention;

FIG. 2 is a fragmentary plan view of the reed frame;

n PIG. 3 is a plan view of a reed on an enlarged scale constructed inaccordance with the present invention;

FIG. 4 is a plan view of a prior art reed; and

FIG. 5 is a plan view of another prior art reed.

Referring now in greater particularity to the drawings, and firstY toFIGS. l and 2, there will be seen a reed frame 1i) of generallyrectangular configuration having a substantially rectangular opening 12therein. Actually, the reed frame tapers somewhat in depth (front toback) from a maximum at the bass end to a minimum at the treble end,since the treble reeds inherently are of shorter length than are thebass reds. One long side of the frame itl is provided with dependingreinforcing rib means 14, and with an upstanding shelf 16. A pluralityof reeds 1S is secured to the top of the shelf 16 by means of arespective plurality of cap screws or bolts 20 extending respectivelythrough the reeds and threaded into the raised portion or shelf 16 ofthe reed frame 10. The reeds are made of metal, conveniently steel,.although other resilient metals can be used. Each reed at its free endis provided with a weight 22 for tuning, and for emphasizing thefundamental rnode of vibration.

The yopposite long side of the reed frame 10 has an insulating spacer 24extending .therealong, and a capacitive pickup Z6 is secured thereto.The pickup and insulating spacer may be held in place by means such asbolts and washers 28 extending through the pickup and through theinsulation and threaded into the reed frame. As will be appreciated,rthe bolts 28 are electrically insulated from the pickup, as by means ofa conventional bushing. The pickup 26 conveniently is of metal, aluminumbeing a preferred example, and is of generally comb-like configurationcomprising a plurality of slots 29 into which the free ends of the reeds18 extend for vibration. Fingers 39 are defined between the slots 29,and these lingers extend between adjacent reeds. As is shown in FIG. 1,the top of each reed is substantially coplanar with the bottom .of thepickup 26. Furthermore, the thickness of the pickup is such that a reedgenerally does not vibrate above the top .of the pickup, while it doesvibrate below the pickup through at least 18() degrees of each vibratingcycle.

A rail 32 extends parallel to the frame 1li, and is secured theretothrough the intermediary of a case (not shown), or by means of suitablebrackets (not shown). The rail 32 is provided with a plurality of buttiianges 34 on which is pivotally mounted a like plurality of hammers 36,each having a felt head or impulsing member 38. A padded rest 40 extendsbeneath the hammers, as shown. Each hammer is provided near the buttthereo-f with an underlying recess 42, and the upper end of a jack 4dbears within each recess. The jacks are respectively actuated by more orless conventional piano actions (not shown).

Another rail i6 extends parallel to the long dimension of the frame 10and is disposed close thereto. A plurality of damper release levers 4Sis mounted along the rail 46, respectively by means of damper anges 50.Each damper release lever is provided with a pad S1 of resilientmaterial, such as felt, bearing against a respective reed 18 to damp orinhibit vibration thereof. At the opposite end of each damper lever 48,there is a connection indicated at 52 with a damper release rod S4suitably connected to the piano action in a manner not shown, wherebyeach damper pad 51 is lifted from engagement with the corresponding reed18 before engagement of the corresponding hammer head 38 therewith.

Reference now should be had to FIG. 3 for a detailed understanding ofthe reed forming the subject matter of this invention. Thus, the reed 18is provided with a generally rectangular base 56 having an aperture 58therethrough through which the respective bolt or cap screw 20 extendsto clamp the base 56 against the raised portion or shelf 16 of the reedframe 10. The reed further has a tongue 69 extending from the base 56 toa free end 62, beneath which is positioned the weight 22. The tongue isprovided with parallel edges throughout the major portion of its length.The remainder of the reed comprises a long tapered portion.Specifically, the tapered sides 64 extend from the line a-a at the limitof the base 56 forming an external shoulder therewith, to the line b-b.The reed sides or longitudinal edges 66 are parallel from this point tothe extremity or free end 62.

No denite limits can be set as to the length of the tapered portion ofthe reed relative to the portion having parallel sides. It will beobserved in the drawing that the taper comprises roughly 25 percent ofthe reed tongue,

and this may be considered to be typical. The proportion is empiricaland is not constant from one reed to another. However, it will beunderstood that the curved taper (the distance from line a-a to lineb-b) would generally be on the order of 20-,35 percent and would neverbe less than substantially l0 percent and would never be more thansubstantially 50 percent of the total length of the reed tongue.Typically, the hammer head strikes the reed tongue outwardly of thetapered area.

By extended simulated life tests, it has been found that a reed as shownin FIG. 3, when impulsively excited to oscillations at extreme amplitude(as by striking with the hammer head 38) eventually will break anywherein the region bounded by the lines a-a and b-b.

A supposedly improved prior art reed is indicated at 74 in FIG. 5. Thisreed has a base 76 joined to a tongue 78 by straight tapered sidesbetween the lines a--a and b-b. This reed also will break along the lineb-b. In short, both of the reeds in FIGS. 4 and 5 are subject tofracture at a well-dened location, whereas the reed in FIG. 3, with thelong curved taper has no well-defined area of fracture. Hence, by actualtest, the reed of FIG. 3 lasts longer by a factor of about four to onethan does the reed in FIG. 4 when submitted to impulse excitation.

Furthermore, in about the lowest twenty notes of a piano, the reedshaped as in FIG. 3 has been found to give a substantially better soundthan that shaped as in FIG. 4. The reasons for this are not at thepresent time fully understood. However, it is thought that in the reedof FIG. 3, the fundamental mode of vibration tends to dominate somewhatmore over the inharmonic partials than in the usual reed of FIG. 4 withthe longer parallel sides.

lt might be thought that a reed with straight tapering sides would bedesirable as providing no denite fracture line. This would be the sameas if the line b-b in FIG. 5 were moved all of the way out to the end ofthe reed, with a uniform straight taper from the line a-a to the linebb. However, such a reed is highly undesirable. L

lt provides a very low Q, and this leads to an extremely undesirableringing time.

Operation of the combination shown in FIGS. 1 and 2 will be obvious tothose skilled in the art. A more or less conventional piano key isdepressed and acts through a more or less conventional action to raisethe jack 44 thereby sending the hammer head 38 up into impulsiveengagement with the reed 1?. At the same time, the action has loweredthe damper release rod 54 to move the damper pad 51 up out of engagementwith the corresponding reed 18, to allow free vibration thereof. Theaction, as is usual, holds the damper in retracted position as long asthe key is depressed.

An electrostatic eld is established between the reeds 1S and the pickupZ6 by establishing a direct current potential therebetween. Preferably,the reeds and the reed frame 1t) are at ground potential, while thepickup is maintained at an elevated potential through a resistor from asuitable source of direct current potential. Upon vibration of one ormore reeds, the capacity between the vibrating reed or reeds and thepickup 26 changes, thereby developing a complex alternating currentpotential across the resistor. The potential developed across theresistor is suitably amplified and transduced to provide an audible,piano-like sound.

vChanges in structure relative to the specific example shown anddescribed herein may Well occur to those i skilled in the art, and willbe understood as forming a part of the invention insofar as they fallwithin the spirit and scope of the appended claims.

This invention is claimed as follows:

1. A vibratory reed for use as in a musical instrument comprising a baseadapted to be secured to a mounting surface, and a at tongue havinglateral and longitudinal dimensions extending freely out from said base,said tongue having a curved inward taper extending out fromsaid basemerging into substantially parallel edges, said curved taper comprisinga substantial portion of the total length of said tongue and having alength greater than the transverse dimension of said tongue.

2. A vibratory reed for use as in a musical instrument comprising a baseadapted to be secured to a mounting surface, and a flat tongue havinglateral and longitudinal dimensions extending freely out from said base,said tongue having a curved inward taper extending out from said basemerging into substantially parallel edges, said curved taper comprisingbetween substantially 10 and 50 percent of the total length of saidtongue and having a length greater than the transverse dimension of saidtongue.

3. A vibratory reed for use as in a musical instrument comprising a baseadapted to be secured to a mounting surface, and a at tongue havinglateral and longitudinal dimensions extending freely out from said base,said tongue having a curved inward taper extending out from said basemerging into substantially parallel edges, said curved taper comprisingbetween substantially 20 and 35 percent of the total length of saidtongue and having a length greater than the transverse dimension of saidtongue.

4. A vibrating reed arrangement for use as in a musical instrumentcomprising a fixed mounting base, a reed including a base and a tonguehaving lateral and longitudinal dimensions extending freely outtherefrom, means mounting said reed base on said mounting base, saidreed tongue having a curved inward taper extending out from the reedbase merging into substantially parallel edges of said tongue, saidcurved taper comprising a substantial portion of the total length `ofsaid tongue and having a length greater than the transverse dimension ofsaid tongue, and a striker member adapted impulsively to engage saidreed tongue to set Said reed tongue in free, decadent vibration.

5. A vibrating reed arrangement for use as in a musical instrumentcomprising a fixed mounting base, a reed including a base and a tonguehaving lateral and longitudinal dimensions extending freely outtherefrom, means mounting said reed base on said mounting base, saidreed tongue having a curved inward taper extending out from the reedbase merging into substantially parallel edges of said tongue, saidcurved taper comprising a substantial portion of the total length ofsaid tongue and having a length greater than the transverse dimension ofsaid tongue, and a striker member adapted impulsively to engage saidreed tongue outwardly of said tapered portion to set said reed tongue infree, decadent vibration.

6. A vibratory reed as set forth in claim 3 wherein the curved taper isa non-circular arcuate curve.

References Cited in the file of this patent UNITED STATES PATENTS Radtkeet al. Feb. 2, 1943

1. A VIBRATORY REED FOR USE AS IN A MUSICAL INSTRUMENT COMPRISING A BASEADAPTED TO BE SECURED TO A MOUNTING SURFACE, AND A FLAT TONGUE HAVINGLATERAL AND LONGITUDINAL DIMENSIONS EXTENDING FREELY OUT FROM SAID BASE,SAID TONGUE HAVING A CURVED INWARD TAPER EXTENDING OUT FROM SAID BASEMERGING INTO SUBSTANTIALLY PARALLEL EDGES, SAID CURVED TAPER COMPRISINGA SUBSTANTIAL PORTION OF THE TOTAL LENGTH OF SAID TONGUE AND HAVING ALENGTH GREATER THAN THE TRANSVERSE DIMENSION OF SAID TONGUE.